present perfect progressive for a negative sentence

I haven't played the piano for ages means that the last time I played the piano was ages ago.

Will it be possible to write that

I haven't been playing the piano for ages

What would that mean?

Before I stop playing it, I used to play very often.

and that

I have not been sleeping for 5 days.

Would that mean that I have not slept well for 5 days but before this I used to sleep very well.

I haven't been hanging about all day, I have helped my brother.

Does that mean that most of the day I helped my brother and could not hang about a lot.

If a native (American-English) speaker wished to say that the last time he played piano was very long ago, he would say:

I haven't played the piano in ages.

Haven't been playing is a very, very unlikely choice of tenses when an AmE speaker wishes to convey that meaning. The continuous/progressive just doesn't work there for that meaning.

Consider:

I haven't been speaking to her for ages.

An American speaker would understand that sentence to mean "I have been giving her the cold shoulder for a long time now. I am angry at her and holding a grudge." Whereas

"I haven't spoken to her for ages."

means "It has been a long time since she and I have conversed."